Can Canon cameras support pixel binning?

I get great results from my Canon ELPH using CHDK but the problem that keeps me thinking of getting a mirrorless or DSLR is dynamic range.Is there any part of the Canon low level hardware interface that allows for pixel binning to to increase dynamic range?Sigma uses this technique in the Quattro cameras and it lets them gain an f-stop. If it could be used in my ELPH running CHDK it would be a great thing. I'd be happy to get 4MP photos with an additional f-stop than the current 16MP with blown highlights etc.Thanks.

Is there any part of the Canon low level hardware interface that allows for pixel binning to to increase dynamic range?

The special scene modes like "low light", "ISO 3200" etc generally use some kind of binning. We don't directly control this, but using CHDK, you can force the ISO back to normal levels. However, binning on a bayer filter sensor hurts quality in other ways, and CHDK currently doesn't have the ability to save the binned raw data in these modes. If the subject allows, doing regular multi-exposure HDR or median stacking is probably a better option. Just using CHDK raw will let you salvage highlights that are blown out in the jpeg.

Basically it means averaging pixels before digitization, which reduces read noise, but not dark current noise.

Simply resizing the images to half does almost the same thing. Noise is reduced by the square root of the number of pixels averaged, resizing to half averages 4 pixels, so noise is reduced by sqrt(4)=2.

The read noise is only a small amount anyhow (some cameras are even called ISO invariant). Best dynamic range is usually the lowest ISO. Use high quality noise reduction as well.

Just a quick note, I think you could do what you want with imagemagick, that is averaging are groups of pixels. It automatically calls dcraw for raw files as well. I'll try to develop the command line for this if I can remember.

If when shrinking (minifying) images the original image is some integer multiple of the new image size, the number of pixels averaged together to produce the new pixel color is the same across the whole image. This is a special case known as 'binning' and is often used as a method of reducing noise in image such as those generated by digital cameras, especially in low light conditions.

I can also add that the standard deviation of the noise (assuming it has a normal distribution, which the read noise does as that's a thermal noise (but not the light itself which has Poisson distribution), will be reduced by

For comparison, here's how noise the equivalent of just one green pixel is. It turns out lighter, because it's not being averaged with the other colours. Kinda hard to make fair comparisons. Have to think about this.